1. Scope of Invention
This invention relates generally to apparatus for punching holes in flat or sheet material, and more particularly to a precision punch assembly and guide body/matrix body assembly and method of punch assembly installation therein.
2. Prior Art
A high degree of accuracy is required in the alignment of three piece punch set assemblies when installed into guide body/matrix body assemblies used in alignment hole placement in high resolution film or plate media for imagers or imagesetters. Many imagers now incorporate internal punching systems that punch registration holes in film and plate media which, after exposure, are used in multiple layers photographic reproduction. The punched holes initially align each media sheet when each image is exposed and, thereafter, aid in precisely registering the images on the stack of two or more media layers in plate making for printing presses.
These internal punch systems require extremely high accuracy with very tight dimensional tolerances. The tolerances for punch-to-matrix body is typically +/-0.0002", while the accuracy of alignment with respect to parallelism and perpendicularity of the punch assembly is typically +/-0.0002" as well.
A common method for accomplishing the required precision alignment of each punch set assembly is by using machinery to form holes to receive the punch guide and punch matrix with extremely high accuracy in combination with very delicate assembly techniques. Thus, the dependency upon the machining process to establish the necessary accuracy is both labor intensive and costly as the machinery used to accomplish this degree of accuracy is considerably higher in equipment costs.
A method of making precision die sets is disclosed in U.S. Pat. No. 3,504,576 invented by Silberman. However, this reference teaches the utilization of a curable adhesive for permanently securing guide posts between a die shoe or holder and a punch holder, the curable adhesive being placed between slightly enlarged holes formed in the die shoe and the lower end of each guide post.
Norell in U.S. Pat. No. 5,303,618 teaches a punch die used to punch minute via holes in ceramic wafers subsequently used in integrated circuit construction. After forming oversized holes, a multiplicity of punch pins are then pressed into the three layer sandwich and epoxied thereto to create an inexpensive punch die which then cooperates with a mechanically drilled die plate covered with a punch pin receiving perforated skin.
In U.S. Pat. No. 3,999,279, O'Neal discloses a method of making a punch assembly which utilizes a plastic resin to form multiple perforations in a frame associated with a punching mechanism for multiple selective perforation of a computer compatible card for use with a punch selector bank.
The above prior art references all deal primarily with the use of a curable or hardenable adhesive or epoxy associated with the equivalent of only one aspect or component of a punch set assembly. Therefore, the degrees of freedom which are permitted is thus limited and therefore the overall accuracy and precision with which the punch and associated punch guide and punch matrix of a three part punch assembly may be aligned is thus limited.
The present invention provides a method and combination punch set assembly and guide/matrix body assembly which greatly increases the accuracy with which the punch set assembly may be installed. By allowing the punch matrix and the punch guide to be freely moved in limited fashion about all degrees of freedom associated therewith between the guide body and the matrix body, very precise alignment and orientation of each punch set assembly and with respect to all other such punch set assemblies installed into a given guide/matrix body assembly is highly increased.